magnetic strip

[nevdull] found himself in possession of a magnetic card reader. What else was he to do but show us all how to read from it using an AVR? He goes through the basics of how the card reader works, as well as how to detect the different card states such as entering, reading, leaving. There is source code to download to try for yourself, but unless you have the same reader, you’ll have to do some modifications. While this doesn’t get you all the way to reading the complete content off of the card, its a great start. Maybe you guys can help him finish up the last bits.

After building a USB magnetic stripe reader, [David Cranor] has found a way to fool a magnetic stripe reader using a hand-wound electromagnet and an iPod. The data on a card is read and stored on a computer, then encoded as a WAV file using a C++ program. The iPod plays the WAV file with the data through a single-stage opamp amplifier connected to the headphone jack. The amplifier is used to drive the electromagnet. Video embedded after the jump.

Don’t get your hopes up just yet on strolling through high security installations using this little device. It can only replay the data from a card that has been recorded. If you don’t have a known working card, it won’t get you very far.